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References: <20221111235341.567987-1-jim.cromie@gmail.com>
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From:   jim.cromie@gmail.com
Date:   Fri, 11 Nov 2022 16:58:24 -0700
Message-ID: <CAJfuBxzNtSfZjesPMH4eaovAYKgrGN0NeAD1VtbWwFokRBEG3w@mail.gmail.com>
Subject: Re: [PATCH 1/1] vmlinux.lds.h: improve BOUNDED_SECTION macros
To:     linux-kernel@vger.kernel.org, jbaron@akamai.com,
        gregkh@linuxfoundation.org
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crap, missed something. lemme fix and resend.

On Fri, Nov 11, 2022 at 4:53 PM Jim Cromie <jim.cromie@gmail.com> wrote:
>
> 1- replace _s_ & _e_ with the more visibly obvious _BEGIN_ & _END_.
>
> 2- add a new _HDR_ linker symbol before the KEEP(*(.gnu.linkonce.##_sec_)).
>    This gives the optional header record an extern'd name/address,
>    which is "_hdr_", b4/after the _sec_/_label_.
>
> 3- move existing _BEGIN_ linker symbol after the KEEP.
>    This insures the extern'd name always points at the data,
>    independent of whether a header has been defined.
>
> NOTE: if (start - hdr) { /* section has a header record */ }
>
> Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
> ---
>  include/asm-generic/vmlinux.lds.h | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index cfad4511cd68..c9b204b0364c 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -199,20 +199,22 @@
>  # endif
>  #endif
>
> -#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _s_, _e_)            \
> -       _s_##_label_ = .;                                               \
> +#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
> +       _HDR_##_label_ = .;                                             \
>         KEEP(*(.gnu.linkonce.##_sec_))                                  \
> +       _BEGIN_##_label_ = .;                                           \
>         KEEP(*(_sec_))                                                  \
> -       _e_##_label_ = .;
> +       _END_##_label_ = .;
>
> -#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _s_, _e_)           \
> -       _label_##_s_ = .;                                               \
> +#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
> +       _label_##_HDR_ = .;                                             \
>         KEEP(*(.gnu.linkonce.##_sec_))                                  \
> +       _label_##_BEGIN_ = .;                                           \
>         KEEP(*(_sec_))                                                  \
> -       _label_##_e_ = .;
> +       _label_##_END_ = .;
>
>  #define BOUNDED_SECTION_BY(_sec_, _label_)                             \
> -       BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
> +       BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop, _hdr_)
>
>  #define BOUNDED_SECTION(_sec)   BOUNDED_SECTION_BY(_sec, _sec)
>
> --
> 2.38.1
>